JPH11309400A - Photocatalytic film coating equipment - Google Patents

Abstract

(57) Abstract: Provided is a photocatalyst film coating method and a coating apparatus capable of forming a photocatalyst film or the like on only one surface of a glass substrate by a dip coating method. A nozzle (1) is disposed near the surface of a coating material (3) and forms a meniscus of the coating at a tip end for discharging the coating.
An imaging means 1a for imaging the shape of the meniscus at the tip of the nozzle 1, a storage tank 4 for storing paint to be supplied to the nozzle 1, and a vertical position of a liquid surface of the paint in the storage tank 4 is detected. An up-down mechanism 7 that includes a detection unit 6 and the storage tank 4, and that changes a vertical position of the storage tank 4 with respect to the position of the nozzle 1 based on information from the imaging unit 1 a and the detection unit 6; An interval changing mechanism for changing the interval between the surface of the coating material 3 and the tip of the nozzle 1 so that the meniscus of the tip of the nozzle 1 is brought into close contact with the nozzle 1, and the tip of the nozzle 1 on this surface along the coating material 3 And a slide mechanism 9 that can change the position of the slide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for coating a glass substrate with a photocatalytic film or the like.

[0002]

2. Description of the Related Art A technology has been developed in which a photocatalytic film mainly composed of titanium oxide (TiO2) is coated on a glass substrate and the oxidative decomposition power is used.

For example, Japanese Patent Application Laid-Open No. 6-278241 discloses that a photocatalytic film is formed on a glass substrate as a building material to prevent odor in an indoor space or stain on the surface of the glass substrate.

[0004] As a coating method of such a photocatalytic film, there are spray coating, dip coating, spin coating, vacuum deposition and the like.

According to these coating methods, a photocatalytic film can be formed on a glass substrate surface with a substantially uniform film thickness.

[0006] By the way, a glass substrate on which a photocatalytic film is formed has been developed for use as a light-transmitting cover by disposing it in a light-transmitting opening of a lighting device.

According to this lighting device, the photocatalytic film is activated by the ultraviolet light contained in the sunlight or the light emitted from the light source of the lighting fixture, so that the dirt component adhering to the light transmitting cover is decomposed, and the cleaning work is performed. An illumination device having a self-cleaning action with reduced frequency can be provided.

[0008]

The glass substrate used for a light-transmitting cover for a lighting device needs to have as high a visible light transmittance as possible, and the coating method is to add a liquid material such as a metal alkoxide to a liquid. After forming the metal oxide layer by the decomposition method, a method of firing at a high temperature is desirable. In order to form such a solvent by a hydrolysis method, a dip coating method is generally used.

However, in the dip coating method, even when it is necessary to form a film only on one surface of the glass substrate, the film is formed on both surfaces.

[0010] In addition, a glass substrate or the like used for a light-transmitting cover for a lighting device has a packing abutted on the peripheral edge thereof. No film is formed.

In order to partially form the photocatalyst film in this way, a masking tape is applied to the surface of the glass substrate on which the photocatalyst film is formed, and coating is performed. Then, the masking tape is removed to form a film non-formed portion. doing.

The present invention has been made to solve the above-mentioned problems, and a photocatalyst film is formed on only one surface of a glass substrate by a dip coating method, and the formed photocatalyst film has a required and uniform thickness. It is an object of the present invention to provide a photocatalyst film coating device that can be formed at a high speed.

[0013]

According to a first aspect of the present invention, there is provided a photocatalyst film coating apparatus which is disposed near a surface of a material to be coated and forms a meniscus of the paint at a tip for discharging the paint. Imaging means for imaging the shape of the meniscus at the nozzle tip, a storage tank for storing the paint to be supplied to the nozzle, detection means for detecting the vertical position of the liquid level of the paint in the storage tank, and the storage tank A vertical mechanism for changing the vertical position of the storage tank with respect to the position of the nozzle based on information from the imaging means and the detecting means, and a surface of the material to be coated so that the meniscus at the tip of the nozzle is brought into close contact with the material to be coated. And a slide mechanism capable of changing the position of the nozzle tip on this surface along the surface of the coating material. It is characterized in.

In the present invention, the nozzle is provided with a portion for forming a meniscus at its tip, and its shape is arbitrary. The nozzle may be installed near the lower surface of the glass substrate, and the nozzle tip itself may be configured to be vertically variably controlled.

The shape of the nozzle tip is determined by the desired meniscus shape. This nozzle can also apply a Teflon coating to quickly bring the liquid to be coated into a predetermined meniscus form.

The container and the nozzle of the storage tank are communicated with each other so that the liquid in the container can flow to the tip of the nozzle. The meniscus due to the surface tension is applied to the tip of the nozzle by utilizing the water pressure of the liquid in the container and the nozzle. A form is formed.

The liquid to be coated is adhered to the lower surface of the glass substrate by bringing a roller having an up-and-down mechanism for supporting the glass substrate with respect to the nozzle holding the meniscus form close to the glass substrate.

Thereafter, while the liquid is adhered to the glass substrate in a meniscus form, the substrate is chucked and a uniform film is formed while being conveyed by a convey actuator capable of moving in the horizontal direction.

According to the photocatalytic film coating apparatus of the present invention, a photocatalytic film similar to the dip coating method is formed on only one surface of the glass substrate by hydrolysis.

In addition, an interval changing mechanism for changing the interval between the surface of the material to be coated and the tip of the nozzle when the glass substrate is conveyed is provided. Can be set as desired.

Further, there is provided imaging means for imaging the shape of the meniscus at the tip of the nozzle, and detection means for detecting the vertical position of the liquid surface of the paint in the storage tank. The vertical position of the storage tank with respect to the position of the nozzle is changed by the vertical mechanism based on this to adjust the shape of the meniscus, so if the vertical position of the storage tank is finely adjusted, the shape of the meniscus can be adjusted very accurately. Become. That is, it is relatively easy to finely adjust the vertical position of the storage tank,
Thus, fine adjustment of the paint extraction amount is easier than fine adjustment of the paint extraction amount using a general pump device or the like.

Furthermore, since the shape of the meniscus is adjusted as described above based on information from the imaging means for imaging the shape of the meniscus, it is possible to adjust the shape of the meniscus very accurately from this point as well.

Although the present invention is an apparatus most suitable for forming a photocatalytic film, the film to be formed can be applied to a device other than the photocatalytic film.

According to a second aspect of the present invention, in the photocatalytic film coating apparatus according to the first aspect, the detecting means is a transmission type sensor having a detection direction fixed at a proper angle with respect to the liquid surface of the paint. Coating equipment characterized by the following.

According to the photocatalyst film coating apparatus of the present invention, in addition to the operation of the photocatalyst film coating apparatus according to claim 1, a transmission type sensor whose detection direction is fixed at an appropriate angle with respect to the liquid surface of the paint is provided. Since the height of the liquid level is detected, the height of the liquid level can be detected accurately with a simple configuration, mainly by simply attaching this transmission type sensor to the storage tank, and the amount of paint extracted from the nozzle can be finely adjusted. As a result, the shape of the meniscus can be adjusted with higher accuracy.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a top view showing the coating apparatus of the first embodiment, FIG. 2 is a schematic side view thereof, and FIG. 3 is another schematic side view thereof.

Reference numeral 1 denotes a triangular groove-shaped nozzle for forming a meniscus at the tip end 2, which is supported by the base 1a near the lower surface of the glass substrate 3 to be conveyed.

The tip portion 2 of the nozzle 1 is an elongated structure having a slit formed therein, and both ends are supported by a support 2a.
Supported by A Teflon coating is applied to the upper surface side of the tip portion 2, so that the liquid to be coated can be instantaneously formed into a predetermined meniscus form.

A container 5 is stored in the storage tank 4, and a liquid containing titanium alkoxide as a main component is injected into the container 5.

The container 5 of the storage tank 4 and the nozzle 1 are connected by a communication pipe 1b through which the liquid in the container 5 can flow to the tip of the nozzle, and utilizes the relationship between the water pressure of the liquid in the container 5 and the nozzle 1. Thus, a meniscus form is formed at the nozzle tip 2.

The storage tank 4 is provided with a sensor 6 as detecting means for detecting the liquid level in the container 5. This sensor 6 is a pair of transmission type sensors fixed at an opening angle of 120 ° centered on the perpendicular of the liquid surface, and the ink 4 itself is moved up and down by the output of the sensor 6 to constantly maintain the liquid surface level. . For this height adjustment, a jack that moves up and down by using a stepping motor is provided as the up and down mechanism 7.

On the side of the nozzle 1, an imaging means 1a for imaging a meniscus formed at the tip of the nozzle 1 is provided. This imaging means 1a is, for example, a CCD camera. The imaging means 1a is arranged so as to image the meniscus from one end side in the longitudinal direction of the nozzle 1, but is provided at another position, for example, a position where the meniscus can be imaged from an oblique direction intersecting the longitudinal direction of the nozzle 1. You may. Further, the imaging means 1a may be attached to the nozzle 1.

Then, based on the information from the sensor 6 and the image pickup means 1a, the vertical mechanism 7 is operated by a control circuit (not shown) provided in the vertical mechanism 7 (not shown), and the height position of the storage tank 4 is controlled. .

As described above, by keeping the meniscus shape of the nozzle tip 2 constant, the amount of the liquid agent used, the film thickness and the like can be controlled.

On the other hand, the glass substrate 3 is supported at four points by a transfer device 9 comprising a one-axis robot as an actuator having a chuck mechanism 8 and a roller 10 having an interval changing mechanism.

The liquid agent to be coated is adhered to the lower surface of the glass substrate 3 by bringing the tip 2 of the nozzle 1 holding the meniscus form close to the glass substrate 3 by an interval changing mechanism.

Then, a uniform film is formed while the liquid is adhered to the glass substrate 3 in the form of a meniscus while being conveyed by the uniaxial robot as the conveying device 9. At this time, the tip width 2 of the nozzle 1 operates the coating width control means 11 having a stepping motor movable vertically with respect to the moving direction of the glass substrate 3 in conjunction with the operation speed of the one-axis robot 9. It is possible to adjust the meniscus length in the extending direction of the tip 2. Further, if the coating width is continuously controlled in accordance with the operation speed of the glass substrate 3, a coating film having a curved line can be formed.

FIG. 4 is a cutaway perspective view showing an enlarged part of the nozzle 1 of the second embodiment. The distal end portion 2 has two L-shaped cross-sections 2b each having a tapered portion formed at the top, opposed to each other such that the top has a mountain shape, and a slit 2c is formed at the center. Width regulating body 2d slidable in this slit
Are provided at both ends of the tip 2.

A meniscus is formed in the slit 2c by the liquid material. The width regulating means 2d slides in the width direction in conjunction with the coating width control means, so that the length of the meniscus in the extending direction is reduced. It is regulated.

[0041]

According to the photocatalyst film coating apparatus of the first aspect, an imaging means for imaging the shape of the meniscus at the tip of the nozzle and a detection means for detecting the vertical position of the liquid surface of the paint in the storage tank. The vertical position of the storage tank with respect to the position of the nozzle is changed by the vertical mechanism based on information from the imaging unit and the detection unit to adjust the shape of the meniscus, so if the vertical position of the storage tank is finely adjusted, The shape of the meniscus can be adjusted very accurately. Further, since the shape of the meniscus is adjusted as described above based on information from the imaging means for imaging the shape of the meniscus, it is possible to adjust the shape of the meniscus very accurately from this point as well.

According to the photocatalyst film coating apparatus of the second aspect, in addition to the effect of the photocatalyst film coating apparatus of the first aspect, the transmission direction in which the detection direction is fixed at an appropriate angle with respect to the liquid surface of the coating material. Since the height of the liquid surface is detected by the mold sensor, the height of the liquid surface can be accurately detected with a simple configuration, and the shape of the meniscus can be adjusted even more accurately.

[Brief description of the drawings]

FIG. 1 is a schematic top view showing a coating apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic side view showing the same coating apparatus.

FIG. 3 is another schematic side view showing the same coating apparatus.

FIG. 4 is an enlarged perspective view showing a nozzle tip of the second embodiment;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Nozzle, 1a ... Imaging means, 2 ... Tip part, 3 ... Glass substrate, 4 ... Storage tank, 5 ... Container, 6 ... Sensor, 7 ... Vertical mechanism, 9 ... Conveying device, 11 ... Coating width control means.

Claims (2)

[Claims] 1. A nozzle disposed near the surface of a material to be coated, the nozzle forming a meniscus of the paint at a tip end for discharging the paint;
Imaging means for imaging the shape of the meniscus at the tip of the nozzle; storage tank for storing the paint to be supplied to the nozzle; detection means for detecting the vertical position of the liquid level of the paint in the storage tank; A vertical mechanism for changing the vertical position of the storage tank with respect to the position of the nozzle based on information from the imaging means and the detecting means; and a surface of the material to be coated so that the meniscus at the tip of the nozzle is in close contact with the material to be coated. And a slide mechanism capable of changing the position of the nozzle tip on the surface of the material to be coated along the surface of the coating target material. Characteristic photocatalytic film coating equipment. 2. The photocatalyst film coating apparatus according to claim 1, wherein the detection means is a transmission type sensor whose detection direction is fixed at an appropriate angle with respect to the liquid surface of the paint.